21658993012 has 12 divisors (see below), whose sum is σ = 39210246180. Its totient is φ = 10456065536.

The previous prime is 21658993001. The next prime is 21658993117. The reversal of 21658993012 is 21039985612.

It can be written as a sum of positive squares in 2 ways, for example, as 11059466896 + 10599526116 = 105164^2 + 102954^2 .

It is a super-2 number, since 2×21658993012² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93357613 + ... + 93357844.

It is an arithmetic number, because the mean of its divisors is an integer number (3267520515).

Almost surely, 2^21658993012 is an apocalyptic number.

It is an amenable number.

21658993012 is a deficient number, since it is larger than the sum of its proper divisors (17551253168).

21658993012 is a wasteful number, since it uses less digits than its factorization.

21658993012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186715490 (or 186715488 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 21658993012 in words is "twenty-one billion, six hundred fifty-eight million, nine hundred ninety-three thousand, twelve".